POWER EFFICIENT LASER DIODE DRIVER CIRCUIT AND METHOD

摘要

A voltage mode laser diode driver selectively turns on and off a laser diode. An output stage has an output node configured to be connected to one of the terminals of the laser diode. Depending upon implementation, an active swing controller drives the output stage in a manner that substantially prevents inductive kickback from causing the output node voltage to swinging above the voltage level at the voltage output of the power supply, or swing below ground. The output stage provides a discharge path around the laser diode to shunt current associated with the inductive kickback, and substantially eliminates ringing on the output node of the output stage while the laser diode is off. A power supply controller adjusts the voltage level of the voltage output of the power supply so that current through the laser diode when on and emitting light is substantially equal to a predetermined desired current.